A conventional pneumatic nailer is illustrated in FIG. 1 and generally includes a head 10 connected to pneumatic source and a neck 12 extends from the head 10. A tube 11 is connected to the neck 12 and has a magnet 15 engaged in the tube 11 so as to attract nails 13 in the tube 11 before the nails 13 are ejected into an object 14. In order to maintain the magnetic force of the magnet 15 in the tube 11, the material of the tube 11 has to be especially chosen so that the feature of the magnet 15 will not fail. However, the material of the tube 11 is expensive. Besides, nails 13 in the tube 11 tend to be inclined relative to a longitudinal axis of the tube 11 as shown because the diameter of the tube 11 is larger than the nails 13. Therefore, the nails 13 could be ejected into the object 14 inclinedly. Furthermore, the magnet 15 could drop from the tube 11 by vibration.
The present invention intends to provide a nailer that has a positioning means to securely position the magnet in the tube. A protrusion extends from an inside of the tube to let the nails attracted by the magnet orient a correct direction in the tube.